ToStringWrapperExample.cpp

#include "doctest/doctest.h"
#include "ApprovalTests/Approvals.h"

#include <ostream>

using namespace ApprovalTests;

struct Rectangle3
{

    int x, y, width, height;

    friend std::ostream& operator<<(std::ostream& os, const Rectangle3& rectangle)
    {
        os << "[x: " << rectangle.x << " y: " << rectangle.y
           << " width: " << rectangle.width << " height: " << rectangle.height << "]";
        return os;
    }
};

std::vector<Rectangle3> getRectangles()
{
    return {
        {4, 50, 100, 61},
        {50, 5200, 400, 62},
        {60, 3, 7, 63},
    };
}

TEST_CASE("MultipleLinesCanBeHardToRead")
{
    // begin-snippet: verify_list
    Approvals::verifyAll("rectangles", getRectangles());
    // end-snippet
}

// begin-snippet: to_string_wrapper_example
struct FormatRectangleForMultipleLines
{

    explicit FormatRectangleForMultipleLines(const Rectangle3& rectangle_)
        : rectangle(rectangle_)
    {
    }

    const Rectangle3& rectangle;

    friend std::ostream& operator<<(std::ostream& os,
                                    const FormatRectangleForMultipleLines& wrapper)
    {
        os << "(x,y,width,height) = (" << wrapper.rectangle.x << ","
           << wrapper.rectangle.y << "," << wrapper.rectangle.width << ","
           << wrapper.rectangle.height << ")";
        return os;
    }
};

TEST_CASE("AlternativeFormattingCanBeEasyToRead")
{
    Approvals::verifyAll("rectangles", getRectangles(), [](auto r, auto& os) {
        os << FormatRectangleForMultipleLines(r);
    });
}
// end-snippet

std::ostream& toStringForMultipleLines(std::ostream& os, const Rectangle3& rectangle)
{
    os << "(x,y,width,height) = (" << rectangle.x << "," << rectangle.y << ","
       << rectangle.width << "," << rectangle.height << ")";
    return os;
}

TEST_CASE("AlternativeFormattingCanBeEasyToRead2")
{
    Approvals::verifyAll("rectangles", getRectangles(), [](auto r, auto& os) {
        toStringForMultipleLines(os, r);
    });
}